The present invention relates to on-line and off-line data processing systems and particularly to host computers and portable card computers.
Portable card computers have been proposed for many years and have sometimes been identified as "Smart Cards". The need for portable card computers arises for many reasons. Card computers will replace credit cards and will help to reduce the annular loss from fraud and misuse of credit cards. In the United States alone, the annular loss presently exceeds 800 million dollars and is expected to increase rapidly.
In addition to replacing existing credit cards, card computers will perform many new functions as they become more widely used. For example, card computers will be used to maintain individual personalized records for many diverse transactions including banking, purchases, medical care, government programs, and business expenses. Additionally card computers will be useful as identification devices for building entry, computer access and many other uses.
Credit cards and other cards in wide use today provide simple one-way data transfers during transactions. Typically, data including an account message is embossed on the credit card and also is stored on a magnetic strip along a surface of the card. When the magnetic strip is moved relative to a read head in a card reader, the account message data stored by the magnetic strip is detected by the card reader. Also, the account message embossed on the credit card is readily transferred to multiple-copy voucher slips in many off-line transactions.
Many differnt types of cards are in use today and much equipment is installed for reading the magnetic strips on the cards. Any new card, in order to be practical, should maintain compatibility with the existing magnetic card equipment.
Recently "smart" cards have been proposed for use in connection with automatic tellers, transaction processors and other data processing equipment. These "smart" cards are plugged into a station for exchanging information between the system and the card and, at times, for processing information on the card.
The cards which have hertofore been used or proposed have suffered from signal transfer problems. These problems are manifested as a limitation on the data rate at which information can be transferred between the system and the card. Furthermore, dirt, dust or contact resistance often causes errors in the transfer of information. When mechanical contacts are employed, errors frequently occur due to dirt or dust or due to the failure of the contacts after repeated insertion and withdrawal of pluggable connections. Accordingly, there is a need to increase the reliability of portable cards of all kinds and particularly "smart cards" which maintain compatibility with magnetic strip technology.
In light of the above background, there is a need for improved storage and processing devices which provide compatible and high-speed data transfer and portability.